The Centers for Disease Control and Prevention (CDC) recommends American adults, including seniors, get at least 150 minutes of moderate-intensity aerobic exercise, such as walking, or 75 minutes of vigorous-intensity activities, such as jogging or running, every week to help maintain -- and possibly lose -- weight. The CDC also recommends strength training two (or more) days each week. Many types of physical activity, whether it's walking a dog or digging in your garden, count toward those hours of exercise. And being active for even just 10 minutes at a time counts toward your weekly total. But, still, we aren't doing a very good job with those fitness recommendations. Our biggest excuses? We don't have time. It's too much work.

If you're carrying some extra weight or if you've fallen off the fitness wagon you're not alone. The average American adult weighs 23 pounds (10.4 kilograms) more than what is considered his or her ideal weight, and about 35 percent of us are considered obese (which means weighing more than 20 percent over your ideal weight) [source: Rauh, CDC]. And if things continue as they are currently trending -- bigger waists and more weight -- it's estimated that 42 percent of Americans will be obese by 2030 [source: Begley].

If thoughts of going to the gym or training for a 5k don't motivate you, maybe the monkey bars will. We know how important it is for kids to play -- not only does it engage their imaginations; it also helps them develop dexterity and strength (both physical and mental). But playing is not just kidstuff.

The idea of adults using playgrounds is relatively new to Americans, but outdoor adult fitness areas -- open spaces, stocked with fitness equipment and freely available for anyone to enjoy -- have been gaining popularity in recent years in China, Japan and some European countries. We have our own list of the things we'd like to see in adult playgrounds – so let's hop to it with a classic: the hopscotch court.